1. Field of the Invention
The present invention relates to a hydrodynamically designed hull.
More particularly, the present invention relates to a hydrodynamically designed hull with hydrofoil qualities.
2. Description of the Prior Art
The invention pertains to an aquatic planing hull which is uniquely configured and has attributes which boat hulls of previous design have not been able to attain. While the prior art has recognized to a certain extent the desirability of having hull designs to achieve end results, the hull design of this invention provides a water craft which has relatively small draft and which has low frictional drag characteristics so as to provide high speed and stable performance.
The hull of the instant invention permits relatively shallow draft with a relatively long hull length and a relatively wide hull beam, all while achieving high water velocities, which would not normally be expected considering the conventional power needs of a similarly-sized hull.
Water craft using the hull design of the instant invention will be capable of high speeds, will use significantly less power than other craft of its size and type and because of its unique configuration will require, in the ordinary case, low draft requirements. The hull design permits unusually high maneuverable characteristics and stable performance at high speeds and also allows the craft to turn within its own length.
The hull design also permits the craft to ride relatively high in the water thereby leaving a minimum amount of surface to be wetted by the water so as to decrease the amount of frictional drag created by the hull, as the water craft is being propelled through a body of water.
In the hull of the instant invention, the open concave forward portion of the hull is such that a cushion of air and water is provided, such that the main body of water that the craft is moving through will break at the main keel portion of the hull, which is located rearward of the mid-point.
Because these is a great need for water craft capable of high speeds, many alternative vehicle concepts have been developed in attempts to evade the problem of pounding. Some of these prior art developments are the surface piercing hydrofoils, fully submerged hydrofoils, air cushion vehicles, captured air bubble craft, super critical displacement hulls and submarines. It would be inappropriate to analyze the characteristics of each of these vehicles here, but it should be noted that only submarines and fully submerged hydrofoils have clearly circumvented the pounding problem while all are much more complicated than a planing boat. This added complexity manifests itself in greatly increased first cost, decreased reliability and severe operation limitations of one kind or another.
The planing craft only planes on a small portion of its bottom at high speeds. When such a craft encounters a wave, the lifting area is greatly increased and the craft experiences the upward acceleration which is the most marked feature of pounding. Because of the inertia of the water in the wave, the magnitude of this acceleration is much greater and would be calculated simply from the increase in wetted area. Thus, the problem which exists is derived from the fact that most planing craft have planing surfaces which are much too large. Others have utilized the "deep V" in hull design in order to reduce pounding. Although, it is generally supposed that a deep V somehow cushions the impact, it actually reduces the efficiency of the lifting surface and hence, in effect, constitutes a reduction of the planing surface size for given boat size. Unfortunately, the deep V not only does not reduce the wetted area, but actually increases it thereby leading to higher skin friction drag.
Hydrofoils raise the hull of the boat up out of the water so that high speeds can be obtained but the hydrofoil is limited in rough sea operations by the distance the hull is raised out of the water. Thus, with waves above a certain size, the boat will be subjected to the same severe pounding that ordinary planing craft are subjected to.
Numerous innovations for aquatic planing hulls have been provided in the prior art that are adapted to be used. Even though these innovations may be suitable for the specific individual purposes to which they address, they would not be suitable for the purposes of the present invention as heretofore described.